Modern tandem warheads require an exact time delay between the detonation of individual warheads. System constraints usually require that the delay occur during the warhead detonation sequence. Traditionally delays are implemented by using long lengths, (e.g. 8 feet to 10 feet) of flexible confined detonating cord (FCDC). The flexible confined detonating cord is typically contained in a housing that is attached to one of the warheads. Traditional systems are carried in helicopters and the warheads do not experience the more severe environments experienced in fixed wing aircraft.
Unfortunately, flexible confined detonating cord has a diameter of about 0.25 inches making it undesirable for use in compact spaces requiring relatively longer time delays. Further, devices using flexible confined detonating cord have not been proven to withstand the more severe environments present on fixed wing aircraft. Thus, a more rugged and more compact system is needed to withstand more severe environments such as those found on fixed wing aircraft.
The present invention addresses the shortcomings of presently available explosive delay assemblies by using a much smaller detonating linear product called a mild detonating fuze (MFD) potted into a metallic housing.
The invention provides an explosive delay assembly including a housing. The housing includes a continuous elongated sidewall surrounding a region bounded at one end by a top surface, the top surface including an aperture configured for accepting an end booster where the end booster is attached to a ferrule assembly, the end booster and ferrule assembly are connected to form a mild detonating fuze including an explosive charge. The elongated sidewalls include a groove emanating from the aperture to a top surface and threading around the continuous elongated sidewall and connected to a channel running from the bottom surface to the top surface. The ferrule assembly is wound around the housing within the groove and inserted into the channel to terminate at a top surface region counterbore. The counterbore is filled with an explosive charge.
In one aspect the invention provides an explosive delay assembly that is designed to withstand more severe flight environments as compared to traditional systems using flexible confined detonating cord.
In another aspect of the invention an explosive delay assembly is comprised of a much smaller detonating linear product called a mild detonating fuze (MDF) potted into a metallic housing, that provides for a 50% increase in delay when compared to a system using flexible confined detonating cord of the same volume.
An advantage of the invention is that it provides an explosive delay assembly that can serve as a secure mounting surface for other warhead components, such as initiation splitting devices and safe, arm and fire devices (SAFD).
In another aspect the invention provides an explosive delay assembly having a mild detonating fuze includes an elongated ferrule having a diameter of less than 0.2 inches and a length for providing a predetermined initiation delay when activated.